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Feature Extraction of Localized Scattering Centers Using the Modified TLS-prony Algorithm and Its Applications

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Journal of Systems engineering and Electronics 2002年第3期13卷 31-39页

作者： Wang Jun Institute of Electronic engineering, china Academy of engineering physics, Mianyang 621900, p.r.china Institute of Electronic engineering China Academy of Engineering Physics Mianyang 621900 P. R. China

This paper presents an all-parametric model of radar target in optic region, in which the localized scattering center's frequency and aspect angle dependent scattering level, distance and azimuth locations are modeled as the feature vectors. And the traditional TLS-prony algorithm is modified to extract these feature vectors. The analysis of Cramer-rao bound shows that the modified algorithm not only improves the restriction of high signal-to-noise ratio(SNr)threshold of traditional TLS-prony algorithm, but also is suitable to the extraction of big damped coefficients and high-resolution estimation of near separation poles. Finally, an illustrative example is presented to verify its practicability in the applications. The experimental results show that the method developed can not only recognize two airplane-like targets with similar shape at low SNr, but also compress the original radar data with high fidelity.

关键词： Localized scattering centers Estimation algorithm Low SNr High resolution.

pErFOrMANCE EVALUATION OF SEVErAL FUSION ApprOACHES FOr CCD/SAr IMAGES

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Chinese Geographical Science 2003年第1期13卷 91-96页

作者： WANG Yan-li, CHEN Zhe(School of Automation Science and Electrical engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, p. r. china) School of Automation Science and Electrical engineering， Beijing University of Aeronautics and Astronautics， Beijing 100083， p. r. china

Several image fusion approaches for CCD/SAr images are studied and the performance evaluation of these fusion approaches is completed in this paper. Firstly, the preprocessing of CCD/SAr images before fusion is fulfilled. Then, the image fusion methods including linear superposition, nonlinear operator method and multiresolution methods, of which the multiresolution methods include Laplacian pyramid, ratio pyramid, contrast pyramid, gradient pyramid, morphological pyramid and discrete wavelet transform, are adopted to fuse two types of images. Lastly, the four performance measures, standard deviation, entropy, cross entropy and spatial frequency, are calculated to compare the fusion results by different fusion approaches in this paper. Experimental results show that contrast pyramid, morphology pyramid and discrete wavelet transformation in multiresolution approaches are more suitable for CCD/SAr image fusion than other ones proposed in this paper and the objective performance evaluation of CCD/SAr image fusion approaches are effective.

关键词： image fusion performance evaluation CCD image SAr image

Optimization of Fractal Iterated Function System(IFS) with probability and Fractal Image Generation

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Journal of University of Science and Technology Beijing 2001年第2期8卷 152-156页

作者： Berthe Kya, Yang Yang (Information engineering School, University of Science and Technology Beijing, Beijing 100083, china) Univ Sci & Technol Beijing Informat Engn Sch Beijing 100083 Peoples R China

There are several methods for rendering fractal images based on IFS (Iterated Function System) in computer graphic; but one concern of the computer graphic community has been the efficiency rendering algorithms. The invariant measures arising from IFSp (Iterate Function System with probability) using the probabilistic algorithm are also known as chaos games. The role of these probabilities to generate the image of the attractor has been investigated using a multi-fractal analysis. The conventional choice of probability associated with each set /S/ to generate the attractor in least time possible is introduced, then a new method based on the self similarity and multi-fractal analysis is presented. The efficiency of the new method has been proved over the conventional method.

关键词： optimization of fractal IFS compression IFSp multi-fractal analysis

Mass transfer coefficients in metallurgical reactors

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Journal of University of Science and Technology Beijing 2003年第2期10卷 1-9页

作者： Ying QuMetallurgical engineering School, University of Science and Technology Beijing, Beijing 100083, china Univ Sci & Technol Beijing Met Engn Sch Beijing 100083 Peoples R China

An overview on the application and achievements of physico-mathematicalmodeling of metallurgical processes in china is briefly declared. The important role of coefficientsin model formulation is shown from our experience. The mass transfer coefficients of the slag-metalreactions and the gas-metal reactions are discussed referring to the flow conditions near theinterface. The influence of the surface-active species on the mass transfer and the interfacialreaction is also discussed briefly.

关键词： mass transfer modeling pyrometallurgy reaction engineering interfacial flow stirring power

Max-Min Adaptive Ant Colony Optimization Approach to Multi-UAVs Coordinated Trajectory replanning in Dynamic and Uncertain Environments

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Journal of Bionic engineering 2009年第2期6卷 161-173页

作者： Hai-bin Duan,Xiang-yin Zhang,Jiang Wu,Guan-jun MaSchool of Automation Science and Electrical engineering,Beihang University,Beijing 100191,p.r.china [a]School of Automation Science and Electrical engineering Beihang University Beijing 100191 P. R. China

Multiple Uninhabited Aerial Vehicles (multi-UAVs) coordinated trajectory replanning is one of the most complicated global optimum problems in multi-UAVs coordinated control. Based on the construction of the basic model of multi-UAVs coordinated trajectory replanning, which includes problem description, threat modeling, constraint conditions, coordinated function and coordination mechanism, a novel Max-Min adaptive Ant Colony Optimization (ACO) approach is presented in detail. In view of the characteristics of multi-UAVs coordinated trajectory replanning in dynamic and uncertain environments, the minimum and maximum pheromone trails in ACO are set to enhance the searching capability, and the point pheromone is adopted to achieve the collision avoidance between UAVs at the trajectory planner layer. Considering the simultaneous arrival and the air-space collision avoidance, an Estimated Time of Arrival (ETA) is decided first. Then the trajectory and flight velocity of each UAV are determined. Simulation experiments are performed under the complicated combating environment containing some static threats and popup threats. The results demonstrate the feasibility and the effectiveness of the proposed approach.

关键词： Multiple Uninhabited Aerial Vehicles (multi-UAVs) Ant Colony Optimization (ACO) trajectory replanning collision avoidance Estimated Time of Arrival (ETA)

Improvement of Boxcar Integrator and Its Application to Low resistance Measurement of Inductive Load Coil

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International Journal of Minerals,Metallurgy and Materials 1998年第3期12卷 180-184页

作者： Xisheng Li Shaochun Wang(Information engineering School, University of Science and Technology Beijing, Beijing 100083, china) Information engineering School University of Science and Technology Beijing Beijing 100083 China

A boxcar integrator is described which is suitable for the low-repetition-rate signal processing. This boxcar integrator, named fixed-interval mode boxcar integrator, is able to reject harmonics other than the first harmonic component. It can also decrease the effective time constant In many situations, the antialiasing filter with narrow bandwidth will cause distortion of the input signal. The fixed-interval mode boxcar integrator with suitable gate width can achieve relative high performance without signal distortion because the bandwidth of its antialiasing filter can be wider than that in the fixed-point boxcar integrator. ms boxcar integrator is used as majn part of signalprocessing circult in the low resisance measurement of inductive load coil. The results of experiments show that the fixed-interval boxcar integrator is suitable for low-repetition-rate use.

关键词： signal processing resistance measurement boxcar integrator

A NOVEL INTErprETATION OF CONCENTrATION DEpENDENCE OF VISCOSITY OF DILUTE pOLYMEr SOLUTION

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Chinese Journal of polymer Science 2000年第1期18卷 57-67页

作者： Yan pan rong-shi Cheng college of Material Science and engineering, South china University of Technology, Guangzhou 510641, china college of Chemistry and Chemical engineering, Nanjing University, Nanjing 210093, china S china Univ Technol Coll Mat Sci & Engn Guangzhou 510641 Peoples R China Nanjing Univ Coll Chem & Chem Engn Nanjing 210093 Peoples R China

The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration C-s(dynamic contact concentration) which divides the dilute polymer solution into two regions.

关键词： self-association polymer solution viscosity concentration dependence

STOCHASTIC ANALYSIS MODEL FOr rIVEr WATEr QUALITY AND ITS AppLICATION

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Journal of Hydrodynamics 1999年第3期11卷 89-97页

作者： Wang Chao, Li Yong Department of Environmental engineering, Hohai University, Nanjing 210024, p.r.china (receied Nov.17,1998)

This paper describes the development and application of a new mathematical technique to include stochasticity in environmental models. The techniques are studied to develop stochastic analysis model of the CBOD NBOD DO equations for predicting the river water quality. The CBOD NBOD DO equations are expanded to include stochastic terms. Stochastic terms are separated from non fluctuating terms, and the resulting set of equations is solved simultaneously. Solutions are used to calculating the integral solutions and the distribution moments of the state variables. The moments are used in conjunction with the Fokker planck equation to produce an analytical solution for the probability density functions of the dependent variables. Because the approach produces analytical solutions, it offers greater flexibility than a Monte Carlo approach in treating complex environmental situations. The model is used to calculate water quality for the Qingao river. The calculated results are in good agreement with the Monte Carlo model and field data.

关键词： stochastic analysis distribution moments probability density functions variance covariance distribution functions water quality model

Novel adaptive Hatch filter to mitigate the effects of ionosphere and multipath on LAAS

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Journal of Systems engineering and Electronics 2010年第6期21卷 1046-1053页

作者： Lin Zhao, Liang Li, Ming Sun, and Xiaoxu Wang college of Automation, Harbin engineering University, Harbin 150001, p. r. china college of Automation Harbin Engineering UniversityHarbin 150001P.R.China

It has been proven that carrier smoothing and differential global positioning system （DGpS） are effective to improve the accuracy of pseudorange by reducing the noise in it and eliminating almost all the common mode errors between the ground station and user. However, another issue coming with local area augmentation system （LAAS） is how to find an adaptive smoothing window width to minimize the error on account of ionosphere delay and multipath. Based on the errors analysis in carrier smoothing process, a novel algorithm is formulated to design adaptive Hatch filter whose smoothing window width flexibly varies with the characteristic of ionosphere delay and multipath in the differential carrier smoothing process. By conducting the simulation in LAAS and after compared with traditional Hatch filers, it reveals that not only the accuracy of differential correction, but also the accuracy and the robustness of positioning results are significantly improved by using the designed adaptive Hatch filter.

关键词： Hatch filter adaptive ionosphere delay multipath differential correction local area augmentation system.